The object of the proposed workscope will be the synthesis of gram quantities of metabolites of the environmental carcinogens benzo(b) flouoranthene, benzo(j) fluoranthene, and benzo(k) fluoranthene, and to prepare certain kinds of the metabolites with carbon or tritium labels. All types of derivatives specified in the RFP will be included. The prepared compounds will be distributed to the scientific community through the Chemical Carcinogen Reference Standard Repository operated by the CPCB. The compounds of interest are among the most widespread of the environmental polynuclear aromatic hydrocarbon pollutants.